Click on "line of reflection" and "image." Move around Point A, B and C. Are reflections rigid motions? How do you know?
Move points D and E to modify the line of reflection. What happens when the line of reflection intersects the pre-image?
Move points D and C so that one is on top of the other. What happens to the image, when the pre-image point is on the line of reflection?
Click on "Pre-Image/Image Lengths."[br]I: What do you notice about the lengths:[br](1) AF, A'F [br](2) BG. B'G[br](3) CH, C'H[br]II: What does that tell you about points F, G and H?
Click on "Angle Measures." What do you notice about the angles formed by the line of reflection and the segments AA', BB' and CC'?